U.S. patent application number 11/893187 was filed with the patent office on 2009-02-19 for contingency mode operating method for air conditioning system.
This patent application is currently assigned to American Standard International Inc. Invention is credited to Roger L. Boydstun, Gordon Jeffrey Hugghins.
Application Number | 20090048715 11/893187 |
Document ID | / |
Family ID | 40363590 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090048715 |
Kind Code |
A1 |
Boydstun; Roger L. ; et
al. |
February 19, 2009 |
Contingency mode operating method for air conditioning system
Abstract
An air conditioning apparatus including a heater or furnace
includes a controller for receiving control signals from a
thermostat and from a user interface for initiating a contingency
mode of operation when a signal from the thermostat is not
available. The user interface includes a visual display and
multiple keys for entering the contingency mode which includes
selecting a capacity of heat output of the apparatus and a duty
cycle. The user interface may be disposed in the apparatus cabinet
and connected directly to a microprocessor based controller for the
apparatus. The contingency mode is automatically aborted if a fault
signal is received by the controller, a signal is received from a
thermostat or power to the apparatus is interrupted.
Inventors: |
Boydstun; Roger L.; (Tyler,
TX) ; Hugghins; Gordon Jeffrey; (Jacksonville,
TX) |
Correspondence
Address: |
The Trane Company;Patent Department 12-1
3600 Pammel Creek Road
La Crosse
WI
54601
US
|
Assignee: |
American Standard International
Inc
|
Family ID: |
40363590 |
Appl. No.: |
11/893187 |
Filed: |
August 15, 2007 |
Current U.S.
Class: |
700/276 |
Current CPC
Class: |
G05B 9/02 20130101; G05B
2219/21157 20130101 |
Class at
Publication: |
700/276 |
International
Class: |
G05B 13/02 20060101
G05B013/02 |
Claims
1. In an air conditioning apparatus for conditioning air to be
circulated to an enclosed space, a controller for controlling
operation of said apparatus, and a user interface operably
connected to said controller for inputting selected control
functions by a user of said apparatus, a method of controlling said
apparatus when a signal is not being received by said controller
from a thermostat, comprising the steps of: selecting a contingency
mode of operation by way of said interface; selecting at least one
of a capacity of air conditioning to be produced by said apparatus
and a duty cycle of said apparatus by way of said interface; and
initiating said contingency mode of operation.
2. The method set forth in claim 1 including the step of: aborting
said contingency mode of operation if a fault signal is received by
said controller.
3. The method set forth in claim 1 including the step of: aborting
said contingency mode of operation if power to one of said
apparatus and said controller is interrupted.
4. The method set forth in claim 1 including the step of: aborting
said contingency mode of operation if a signal is received by said
controller from said thermostat.
5. The method set forth in claim 1 including the step of: providing
said controller to include a controller microprocessor and
providing a program for said contingency mode of operation resident
on one of said controller microprocessor and another microprocessor
which may be operably connected to said controller
microprocessor.
6. The method set forth in claim 1 including the step of: providing
said interface to include a visual display and plural user operable
keys for commanding said interface to carry out selected steps to
establish said contingency mode of operation.
7. The method set forth in claim 6 including the step of: selecting
an operating capacity of said apparatus in response to a message on
said display.
8. The method set forth in claim 6 including the step of: selecting
a duty cycle of operation of said apparatus in response to a
message on said display.
9. The method set forth in claim 8 including the step of: selecting
a duty cycle of operation of said apparatus of from 10% to 50%
wherein said duty cycle of 10% includes operating said apparatus
for two minutes and turning said apparatus off for eighteen
minutes, and a duty cycle of 50% comprises operating said apparatus
for ten minutes and turning said apparatus off for ten minutes.
10. The method set forth in claim 9 including a step of: repeating
a duty cycle multiple times per unit of time.
11. The method set forth in claim 1 including the step of:
providing said interface disposed in a cabinet of said
apparatus.
12. In an air conditioning apparatus for conditioning air to be
circulated to an enclosed space, a controller for controlling
operation of said air conditioning apparatus including first and
second microprocessors, and a user interface operably connected to
said controller for commanding selected control functions by a user
of said apparatus, a method of controlling said apparatus in the
absence of a signal being received by said controller, comprising
the steps of: selecting a contingency mode of operation of said
apparatus by way of said interface; selecting at least one of a
capacity of air conditioning to be produced by said apparatus and a
duty cycle of said apparatus; initiating said contingency mode of
operation; and aborting said contingency mode of operation if one
of a fault signal is received by said controller, power to one of
said apparatus and said controller is interrupted, and a signal is
received by said controller from a thermostat.
13. The method set forth in claim 12 wherein: the steps of said
method are carried out at least in part by a program resident on
one of said microprocessors.
14. The method set forth in claim 12 including the step of:
providing said interface to include a visual display and plural
keys for commanding said interface to carry out selected steps of
said contingency mode of operation.
15. The method set forth in claim 14 including the step of:
selecting said capacity to be produced by said apparatus in
response to a message on said display.
16. The method set forth in claim 14 including the step of:
selecting said duty cycle of operation of said apparatus in
response to a message on said display.
17. The method set forth in claim 16 including the step of:
selecting a duty cycle of said apparatus of from 10% to 50% wherein
said duty cycle of 10% includes operating said apparatus for two
minutes and turning said apparatus off for eighteen minutes, and a
duty cycle of 50% comprises operating said apparatus for ten
minutes and then turning said apparatus off for ten minutes.
18. The method set forth in claim 17 including a step of: repeating
a duty cycle multiple times per unit of time.
19. In an air conditioning apparatus for conditioning air to be
circulated to an enclosed space, a controller for controlling
operation of said air conditioning apparatus including at least a
first microprocessor, and a user interface operably connected to
said controller, said interface including a visual display and
plural keys for commanding selected control functions by a user of
said apparatus, a method of controlling said apparatus by way of
said interface in the absence of a signal being received by said
controller from a thermostat, comprising the steps of: selecting a
contingency mode of operation of said apparatus in response to a
message on said display; selecting a capacity of air conditioning
to be produced by said apparatus and a duty cycle of said apparatus
in response to messages on said display; and initiating said
contingency mode of operation.
20. The method set forth in claim 19 including the steps of:
aborting said contingency mode of operation if one of a fault
signal is received by said controller, power to one of said
apparatus and said controller is interrupted, and a signal is
received by said controller from said thermostat.
Description
BACKGROUND OF THE INVENTION
[0001] In the art of air conditioning apparatus or systems,
otherwise known as heating, ventilating and air conditioning (HVAC)
equipment, improvements have provided systems which operate with
thermostats and similar sensors which transmit digital signals to a
system main controller. In the event that a thermostat or other
sensor or control feature which normally sends digital signals is
not available, is defective or becomes disconnected from the system
controller it is not possible to operate the air conditioning
system with a simple timer or manually actuated switch.
Accordingly, there has been a need to develop a means and method
for operating digitally controlled HVAC equipment in a so called
contingency mode when a thermostat or similar type controller is
not functioning properly, is not connected to the system controller
or is currently not installed in the space or spaces for which the
air conditioning equipment is to service. However, the present
invention provides for operating a unit of air conditioning
equipment or system of the general type described above in such a
contingency mode.
SUMMARY OF THE INVENTION
[0002] The present invention provides an improved method of
operating an air conditioning system, particularly a system which
relies on digital signals to provide a call for heating or cooling
to a main controller or control unit of the system.
[0003] In accordance with one aspect of the present invention a so
called contingency mode or method of operating an air conditioning
system is provided wherein a user operable interface is operably
connected to the main or primary system controller for establishing
certain permitted operating modes when a thermostat, normally
connected to the system, is not present or not operable.
[0004] In accordance with another aspect of the invention, a method
is provided for allowing a user of a unit of air conditioning
equipment to select a desired level of equipment capacity, such as
in a multi-stage furnace, for example, and select a desired on/off
duty cycle. The method of the invention provides for placing a
so-called contingency mode computer program or software in a
separate controller or microprocessor which may be included in or
releasably connected to a main system controller. Moreover, the
method of operating in the so called contingency mode may also be
configured as to not be available for use by a user or operator of
the system if a thermostat or similar controller is operably
connected to the system main controller.
[0005] Those skilled in the art will recognize the above mentioned
advantages and features of the invention together with other
important aspects thereof upon reading the detailed description
which follows in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view, in somewhat schematic form, of
a multi-stage furnace operable in accordance with the contingency
mode or method of the present invention;
[0007] FIG. 2 is a diagram illustrating a user interface for
setting and controlling certain parameters of the contingency mode
or method of operating an air conditioning or furnace apparatus;
and
[0008] FIG. 3 is a generalized flow diagram illustrating certain
steps associated with entering the contingency mode of
operation.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0009] In the description which follows like elements are marked
throughout the drawings and specification with the same reference
numerals, respectively. The drawing figures are in somewhat
schematic form in the interest of clarity and conciseness.
[0010] The contingency mode or method described herein may be used
in various configurations of HVAC equipment otherwise known as air
conditioning equipment, including equipment providing for cooling
only, heating only or both heating and cooling. For purposes of
this discussion the invention will be described for use in
conjunction with a multi-stage forced air combustion furnace,
generally designated by the numeral 10 in FIG. 1. The furnace 10
includes a cabinet 12 in which a motor driven air circulating
blower 13 is disposed for circulating air from an inlet opening 12a
through the interior of the cabinet and over heat exchangers 14
which are fired by respective burners 16 in a manner well known.
Combustion fuel, such as natural gas, is supplied to the burners 16
by way of a motor operated valve 18, including a valve controller
20. Furnace 10 may be of a type which includes a heat exchanger
ventilating or inducer blower 22 which draws air and combustion
products through the heat exchangers 14 in a forced manner, also
known to those skilled in the art. Conditioned air is discharged
from the furnace 10 through a discharge opening 12b and is
circulated to and from an enclosed space 24, as indicated by the
air flow direction arrows 13a and 13b in FIG. 1.
[0011] Control of the furnace 10, including control of the
circulating air blower 13, the valve 18 and the ventilating or
inducer blower 22 is the responsibility of a main or primary
controller unit 26 which may be disposed within cabinet 12, as
indicated in FIG. 1. Controller unit 26 includes or is adapted to
be connected to a user interface 28 which is operable to be in
communication with a microprocessor 30 operably connected to a
primary microprocessor 32 of the controller unit 26, see FIG. 2.
Microprocessors or microcontrollers 30 and 32 may be permanently
connected or microcontroller 30 may be a separate plug-in module
with respect to the controller unit 26. A so called communicating
thermostat 34, FIGS. 1 and 2, is shown connected to the
microcontroller 32 for communicating control signals, including a
call for heat, in a known manner. Signals are transmitted between
microcontroller 32 and thermostat 34 by conventional wiring or by
other means, including radio frequency transmission or optical
signals, for example. In this respect thermostat 34 may include its
own microcontroller 35, FIG. 1.
[0012] Refer briefly to FIG. 2, the user interface 28 preferably
includes a visual display 28a and user actuatable keys or switch
actuators comprising an "Enter" key 28b and scrolling keys 28c and
28d for so called up and down scrolling and left/right keys 28e and
28f for selecting menu options shown on the display. Thanks to the
availability of the user interface 28 at the apparatus 10,
including a suitable mounting within the cabinet 12, if power is
supplied to the air conditioning apparatus 10, the apparatus may be
operated in the inventive contingency mode or method even if the
thermostat 34 is not installed or is not operably connected to the
apparatus controller unit 26, for example.
[0013] If the thermostat 34 is operably connected to the controller
unit 26, the so called contingency mode or method will not be
allowed to operate and no contingency mode menu options will be
displayed at the display 28a, as indicated by steps 40 and 42 in
the diagram of FIG. 3. The user interface 28 may be operated to
display certain information related to the particular
identification of the air conditioning apparatus or furnace 10, set
certain operating parameters and determine certain fault conditions
identified by or managed by the controller unit 26. Controller unit
26 is operable to control the motors for the blowers 13 and 22, the
control valve 18 and to receive signals from various sensors,
including pressure sensors and temperature sensors typically
associated with a multi-stage furnace, for example.
[0014] Accordingly, if thermostat 34 is not connected to apparatus
10, is not functioning or has not been installed in space 24, the
contingency mode of operating the apparatus 10 may be initiated by
actuating key 28b. If the contingency mode is not allowed at step
40, FIG. 3, the words "NOT AVAILABLE" may be displayed on line 29a
of the two line visual display 28a. If the contingency mode is
allowed at step 40 the process will proceed to step 44 whereby the
words "CONTINGENCY MODE" will be displayed on line 29a and the
words "STAGE, DUTY CYCLE, and START" will appear on line 29b of the
display 28a. At this point keys 28e or 28f may be used to select
either STAGE, DUTY CYCLE or START. If the apparatus 10 is a
multi-stage furnace it may be set to operate as a single stage, two
stage or three stage. Accordingly, upon selection of STAGE using
the keys 28e and 28f, followed by actuation of key 28b, the words
STAGE or SET CAPACITY will appear on the display as indicated at
step 46, FIG. 3 and the choices "OFF", 1, 2 and 3 will appear on
line 29b. A selection of OFF will result in the controller 26
returning to a stand-by mode and a default value will revert to OFF
if the menu is aborted. At any point in the set up process, if one
of capacity Nos. 1, 2 or 3 is selected the controller 26 will cause
the apparatus 10 to operate accordingly in a first stage, second
stage or third stage furnace operating mode.
[0015] Since there is no thermostat operating to control the on or
off function of the gas valve 18 and burners 16, in addition to the
furnace "capacity" setting a "duty cycle" setting is required to be
selected or set, as indicated at step 48, FIG. 3. By returning to
the contingency mode setup menu, the menu option DUTY CYCLE may be
selected by suitable actuation of the keys or switch actuators 28e,
28f and 28b. On selection of the duty cycle menu or sub-menu the
choices may be a duty cycle, for example, of 10% to 50% in 10%
increments and 10% will be a default value. The default value will
be reverted to once the menu is aborted without entering the
contingency mode or the contingency mode is terminated. A 10% duty
cycle is defined as a cycle wherein the burners 16 are operated for
two minutes and are then off for eighteen minutes and a 50% duty
cycle will fire the burners 16 for ten minutes and then off for ten
minutes. Duty cycles are repeated three times per hour. Upon
completion of selection of the duty cycle at step 48, the process
continues to step 50 whereby the display 28a may prompt the user by
displaying start CONTINGENCY MODE, or "Start C.M." which operation
may be initiated by, for example, actuating key 28b whereby the
contingency mode will begin operation at step 52. If, at step 50,
the user elects no response to the "start contingency mode" query,
the control system or controller 26 will resume normal operation at
step 54. Of course, during operation in the contingency mode, if
any faults are detected in operation of the system or apparatus 10,
including a loss of power, the contingency mode will be aborted at
step 56, FIG. 3.
[0016] In particular, the contingency mode or method of operation
of the apparatus 10 can only be entered at the user interface 28
and can only operate when the apparatus is functioning as a furnace
or is in a heating mode of operation, if such apparatus also
includes an air cooling component, for example. If and when
thermostat 34 is not communicating or transmitting a signal
indicating its presence to the control unit or controller 26, the
contingency mode may be entered by, for example, opening a switch
58, FIG. 2, supplying power to the controller unit 26 and the
motors for the respective blowers 13 and 22. One or more visual
indicators 60 and 62 associated with the controller 26 may be used
to give a visual indication that power has been removed from the
controller 26 and/or the controller 26 is also not receiving a
fault signal. After closing switch 58, the user interface 28 may be
operated by actuating one of the keys 28c or 28d to select
"CONTINGENCY MODE" on the display 28a after which key 28b may be
actuated to show on the display the identifier CONTINGENCY MODE and
"STAGE". At this time a first, second or third stage or capacity of
heating must be selected using the keys 28e and 28f. After the
stage or capacity of the system 10 is selected by actuating the key
28b that capacity value is communicated to the controller 26.
[0017] After selecting the capacity or stage of operation (Stage 1,
Stage 2 or Stage 3) the term DUTY CYCLE and 10% will be displayed
at the display 28a and a duty cycle of between 10% and 50% must be
selected, as previously mentioned. The selection is carried out by
using the keys 28e and 28f while viewing the display 28a. After
selection of the duty cycle the word "START, YES or NO" may be
displayed at display 28a and keys 28e and 28f may now be used to
select YES followed by actuation of key 28b. The user interface 28
may prompt the user again by displaying "ARE YOU SURE" and "NO".
Confirmation may be carried out by scrolling laterally with keys
28e and 28f until the term "YES" appears on display 28a followed by
actuation of key 28b. The contingency mode may be initialized by
opening switch 58 and observing one or the other of indicators 60
and 62 and, when such indicator is extinguished, switch 58 may be
closed again to confirm the contingency mode. The term CONTINGENCY
MODE will appear in display 28a on line 29a, and the capacity or
stage number selected and the duty cycle percent number will be
displayed on line 29b.
[0018] All furnace operating safety features and switches connected
to the controller 26 will be monitored for proper operation of the
apparatus during operation in the contingency mode. Switches
associated with the keys 28c, 28d, 28e and 28f will be inactive
during the contingency mode. The contingency mode of operation will
also cease upon receipt of a signal indicating reconnection or
communication with the thermostat 34, power being removed from the
controller 26 and then restored, any requirement to reset
controller 26 or any fault being detected by the controller which
will result in illumination and/or flashing of one or the other of
the indicators 60 and 62, for example. Accordingly, to purposely
exit the contingency mode the switch 58 may be opened and then
re-closed, for example.
[0019] Accordingly, if a signal is not being received by the
controller 26 from a sensor or a control device, such as the
thermostat 34, a user of the apparatus 10 may select the manual or
so called stand alone or contingency mode of operation, thanks to
the method of the present invention. Those skilled in the art will
appreciate that commercially available controllers, including
microcontrollers or microprocessors, such as the processors 30
and/or 32, may be suitably programmed to carry out the method steps
described herein. Commercially available control components
otherwise known to those skilled in the art may also be used to
provide the controller 26 and the components of the apparatus 10
described hereinbefore.
[0020] Although a preferred embodiment of the invention has been
described in detail, those skilled in the art will recognize that
various substitutions and modifications may be made without
departing from the scope and spirit of the appended claims.
* * * * *